The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713

Details The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713 The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713

Dec 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992aas...18111101s&link_type=abstract

American Astronomical Society, 181st AAS Meeting, #111.01; Bulletin of the American Astronomical Society, Vol. 24, p.1297

Astronomy and Astrophysics

Astronomy

Scientific paper

A heretofore unknown population of faint (R < 22), very blue galaxies (U--B < --0.2 in the observer's frame) has been discovered in the extremely rich intermediate redshift cluster CL0939+4713 (z = 0.41). This population was revealed by an analysis of deep, multi-band (UBRI), wide-field (20x20 arcmin ~ 8x8 Mpc; H_o = 100, q_o = 0.1), CCD images obtained with the KPNO 0.9m. The central wavelengths of the bandpasses used correspond to roughly 2550 Angstroms, 3070 Angstroms, 4640 Angstroms, and 5850 Angstroms in the cluster rest-frame. Galaxy photometry and classification were completed with FOCAS. The radial density distribution of this very blue population indicates a significant enhancement over the field surface density of galaxies with similar colors. While it is likely that some fraction of these galaxies are foreground/background objects, the combination of a large number of objects observed (N ~ 1000) and the large FOV makes it statistically certain that the majority of these objects are associated with CL0939+4713. The very blue observed U--B colors suggest that OB stars contribute significantly to the light of these objects, making it likely that they are either very young or have enhanced SFRs. Large crossing times (~ 5 Gyr) are implied by the radial density distribution and the observed velocity dispersion (sigma = 860 km/s; Dressler & Gunn 1992). The irregular surface density of the very blue galaxies makes it unlikely that they have been virialized. It seems plausible that many of these galaxies are infalling into the cluster for the first time (e.g. Rivolo & Yahil 1983), which might link these galaxies to the faint blue population found in the field (e.g. Colless et al. 1989). Moreover, high resolution imaging suggests that interactions/mergers may play a significant role in the star formation history of both the field (Lilly 1992) and the cluster (Pierce et al. 1992) populations. Thus, these faint, very blue cluster galaxies may have a similar origin and fate as the faint, blue field galaxies.

Affiliated with

Also associated with

No associations

Rating

The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Discovery of a Faint, Very Blue Galaxy Population in CL0939+4713 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1112190